| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 853881 | Procedia Engineering | 2016 | 10 Pages |
Phosphoric acid production is a well-known and mature technology but still has room for improvement and innovation. In that respect, the permanent exchanges between process engineers of plant and design offices are of great value. In the Prayon production site of Engis, we have both and achieve permanent plant improvement due to communication between the divisions.The production plant operates under the Central Prayon Process in operation for more than 40 years. It is a dihydrate-hemihydrate process producing an acid of 32-36% P2O5 with efficiency higher than 98% and a high quality calcium sulfate valorized in the plaster industry.Considering our client requirements, the quality of the calcium sulfate needs to be followed with great care and cannot suffer any deviation. The Prayon tilting pan hemihydrate filter needs to be permanently at its best. The P2O5 content in the calcium sulfate (with a maximum limit at 0.6%) must be carefully controlled during all operation time. Therefore, cleanness of the clothes has to be constantly kept as best as possible to ensure the plant capacity and a maximum P2O5 yield recovery. Moreover, cell cleaning operation must be reduced in order to limit the maintenance and the shut-down costs.To tackle these challenges, a joint team of Prayon production plant, Profile and Prayon Technologies has been established. The cake wash water flow has been optimized in order to improve the cake washing efficiency and minimize the P2O5 losses.Furthermore, a new high pressure oscillating ramp has been designed to greatly improve the cloth wash.Finally, new two parts cell bottom has been implemented for easy removal and cleaning of the filter cell bottom.Overall it allows the Engis plant to save 400 hours of maintenance per year, to lower the shut-down time for cells and clothes cleaning of 2 days per year and to recover 850 tons of P2O5 per year by efficiency improvement.
